1. Field of the Invention
This invention relates generally to connectors, whether single conductor or multiple conductor, and whether intended for use as single connector items, e.g. for making a separable connection to a piece of electronic apparatus, or as a part or parts of a multiple-part line connector assembly, e.g. male and female interconnecting plug and socket items.
More specifically, the invention relates to connectors which provide for suppression of radiated and/or conducted electromagnetic emissions which would be detrimental to proper use of apparatus in which the connector is included. In particular the invention is applicable to fields of use wherein there is necessity for including an electrical or electronic circuit or device having a relatively low signal level which might be adversely affected by such stray emissions, for example thermocouple sensor circuits.
2. Description of the Prior Art
In the prior art of connectors there are disclosures of the use of ferrite material in the following:
(I) U.S. Patents assigned to AMP Inc: U.S. Pat. Nos. 4,699,590, 4,359,620, 3,789,263, Re29,258, 3,735,705, 3,987,380, 4,936,800.
(II) U.S. Patent assigned to The Whitaker Corp: U.S. Pat. No. 5,219,305.
(III) U.S. Patent William Baird Fritz U.S. Pat. No. 3,743,978.
(IV) U.S. Patent assigned to Stanford Research Institute and Amplex Corporation: U.S. Pat. No. 3,533,948.
(V) Un-examined Japanese Patent Application, AMP Inc., 90-032246/05 JO 1279-584-A discloses an electrical connector which has a noise filter with a ferrite head fitted to a terminal lead formed by a central conductor of a feed-through capacitor.
(VI) German Patent assigned to AMP Inc., Auslegeschrift No. 2,058,419 discloses a method for the manufacturer of a high frequency filter from a ferrite tube, which is in the form of a highly compressed tube and which is bonded on its outer surface with a covering of dielectric material, the layer of dielectric material carrying an electrode in the form of a metallic outer sleeve, and a further electrode is provided in similar manner on the inside of the ferrite tube, characterised in that the covering (6) of dielectric material is laid down directly into the outer surface of the ferrite tube (5) by electrophoresis.